基于正交试验的钢丝绳探伤仪结构参数优化

Optimization of structural parameters of wire rope flaw detector based on orthogonal test

在钢丝绳损伤检测中,探伤仪结构设计对钢丝绳损伤检测精度至关重要。针对现有基于电磁的钢丝绳探伤仪各结构参数及参数各种组合研究不充分的问题,提出了一种基于正交试验的钢丝绳探伤仪结构参数优化方法。基于径向磁环磁场分布的理论数学模型和等效磁路理论模型,分析得出影响钢丝绳探伤仪检测精度的结构参数有磁铁长度、磁铁厚度、衔铁厚度、衔铁长度和倒角参数。通过正交试验方法研究了各参数之间的影响等级及影响显著性:各参数对钢丝绳探伤仪检测精度的影响等级为磁铁厚度、磁铁长度、衔铁长度、衔铁厚度和倒角情况,磁铁厚度、磁铁长度和衔铁长度影响显著,在设计钢丝绳探伤仪时应优先考虑,衔铁厚度及倒角显著性不强,可以忽略;磁铁厚度和磁铁长度(<70 mm)的影响随着水平的增长整体呈正相关关系,随着磁铁厚度和磁铁长度的增大,检测精度会明显提升;而衔铁长度整体呈负相关关系,长度越长,检测精度越差。根据上述分析结果,确定了钢丝绳探伤仪各参数优化数值,并对优化前后的钢丝绳探伤仪的磁力线分布、磁场分布及径向、轴向各相位磁感应强度的分布进行对比验证。结果表明:基于正交试验优化后的钢丝绳探伤仪,磁力线分布均匀,对钢丝绳的励磁效果达到2 T以上,漏磁信号明显,不同相位下的损伤信号区别较大;与优化前的钢丝绳探伤仪相比具有磁感应强度大幅度提高、空域分布明显改善、对传感器位置(提离值)的要求相对宽泛的优势,径向检测精度提升了40%左右,轴向检测精度提高约80%,对钢丝绳损伤的感知效果明显提升。

In the detection of wire rope damage, the structure design of the flaw detector is very important to the detection precision of wire rope damage. The research on the structural parameters and their combinations of the existing electromagnetic wire rope flaw detector is insufficient. In order to solve the above problems, an optimization method of structural parameters of wire rope flaw detector based on orthogonal test is proposed.Based on the theoretical mathematical model of magnetic field distribution of radial magnetic ring and the theoretical model of the equivalent magnetic circuit, the structural parameters affecting the detection precision of wire rope flaw detector are analyzed and obtained. The parameters include the length of the magnet, the thickness of the magnet, the thickness of the armature, the length of the armature and the chamfer parameter. The influence grade and significance of each parameter are studied by the orthogonal test. The influence grade of each parameter factor on the detection precision of the wire rope flaw detector is the thickness of the magnet, the length of the magnet,the length of the armature,the thickness of the armature and the chamfer.The thickness of the magnet,the length of the magnet and the length of the armature have significant effects.These should be given priority when designing the wire rope flaw detector.The thickness of the armature and the chamfer are not significant and can be ignored.The influence of the thickness of the magnet and the length of the magnet is positively correlated with the increase of level.With the increase of the thickness of the magnet and the length (<70 mm) of the magnet,the detection precision will be significantly improved.The length of the armature shows a negative correlation trend as a whole.The longer the length,the worse the detection precision.According to the analysis results,the optimized values of the parameters of the steel wire rope flaw detector are determined.The magnetic line distribution,the magnetic field distribution and the radial and axial phase magnetic induction intensity distribution of the steel wire rope flaw detector before and after the optimization are compared and verified.The results show that the optimized steel wire rope flaw detector based on the orthogonal test has uniform magnetic flux distribution.The excitation effect of steel wire rope is more than 2 T.The magnetic flux leakage signal is obvious.The damage signal under different phases is quite different.Compared with the steel wire rope flaw detector before optimization,the steel wire rope flaw detector has the following advantages.The magnetic flux leakage intensity is greatly improved.The spatial distribution is obviously improved.The requirements for the position (lift-off value) of the sensor are relatively broad.The radial detection precision is improved by about40%,and the axial detection precision is improved by about 80%.The perception effect on the damage of the steel wire rope is obviously improved.